S.T.A.L.K.E.R.: Clear Sky, is the stand-alone prequel for S.T.A.L.K.E.R.: Shadow of Chernobyl, a first-person shooter computer game by Ukrainian developer GSC Game World.[3] The game consists of a roughly 50/50 mix of new areas and old, remodeled areas from the previous game. The X-ray graphics engine has been updated to version 1.5 and includes DirectX 10 support (later patch 1.5.06 included DirectX 10.1). Additionally, the AI received an overhaul to accommodate the new faction wars feature.

Clear Sky, as you would expect, goes to the red team. As we have come to expect, though, the GTX 275 sits between the two other NVIDIA cards.